Here's something tangible from many years in business: People will try to keep you in positions you're currently in because you're more valuable to them there. I use to be in sales and when I told my sales rep that I wanted to sell, he gave me the old "but you're so good at client services - you really have a future managing that team" bullshit. Here's what he meant: "You're servicing my book of business and you vacating that position is a threat to my own personal bottom line." Always go with your gut - take big risks and be wary of career advice EVEN from your closest mentors. I would actually advise getting a mentor that's a family friend or something from youth.. someone that has nothing to do with your current career - they may give you straight advice.
There are two rules for success:
Never tell everything you know.
-Roger H. Lincoln"